This application's broad long-term objectives are to gain an understanding for the subtle yet potentially devastating effects that polychlorinated biphenyls (PCBs) have on psychologicalfunctions. PCBs are found everywhere in the world located in the global water supply, air and soil.Developing countries still utilize this potent endocrine disruptor in manufacturing and industry.The United States was forced to end all synthesis and use of the compound in the 1970s, but thetoxin remains ubiquitous, and the effects of exposure to crucial psychological processes during development are unknown. We believe that if we can understand the relationship between PCB Exposure and psychological development, we can work to remove the effects by environmental,nutritional and behavioral means. Our specific aims are to determine exactly what kinds of changes occur in social interaction after perinatal exposure. Our preliminary results stronglysupport an impact of low to moderate PCB on social behavioral expression in both the young neonate and juvenile animal. We intend to utilize three well established social behavioral paradigms to reach these aims: 1) Social Recognition Test- a test for social memories of young rats that examines how sensory cues are held in storage and subsequently direct approach behavior, 2) Social Play Behavior-A measure for the level of social interaction between juveniles and 3) Social Port Investigation-A measure of social-directed behavior in young adult rats. In addition, we will examine the relative environmental-genetic contributions on the social behavioral effects with a cross-fostering design and critically, examine general motor function in the animals to better grasp how our changes in social function relate to motoric alteration after PCB exposure. All of these paradigms 1) contain high reliability between animal models and are thought to be valid measures of social-directed behavior, 2) have been shown to reveal behavioral and physiological relationships essential to social development and 3) provide innovative profiles of social function that span development from neonate to young adulthood. Finally, our interdisciplinary team will investigate the relationship between these behavioral functions and endocrine status, specifically analyzing changes in neurohormones purportedly involved in social function such as oxytocin and vasopressin. Our ultimate mission merges with the National Institute of Child Health and Development in that we are interested in optimizing patterns of psychological organization and reducing in the influence of harmful factors like teratogens from the developmental process.